Engineering Questions with Answers - Multiple Choice Questions
Distillation Design MCQ’s – Key Components of Multicomponent Distillation
1 - Question
For the light key component, Equilibrium relation is
a) yK=x
b) Kx=y
c) Depend upon trays
d) Can’t be specified
View Answer
Answer: a
Explanation: Here Kx=y is the equilibrium relation, which does not depends upon the number of trays or the vice versa relation i.e. Kx=y representing x and y moles of gas and fluid.
2 - Question
If the fractional recovery of light key in the distillate is FR, then light key in the feed is
a) DxD= (FRD)+FxLK
b) DxD= (FRD)/FxLK
c) DxD= (FRD)FxLK
d) DxD= (FRD)
View Answer
Answer: c
Explanation: The definition of the fractional recovery is DxD= (FRD) FxLK, while gives us the material balance on feed and distillate DxD= (FRD).
3 - Question
For multi-component systems, Underwood Equations gives
a) Minimum Reflux
b) Minimum Strip
c) Maximum Reflux
d) Minimum Trays
View Answer
Answer: a
Explanation: Underwood Equations gives Minimum Reflux, Fenske’s equation gives minimum Trays and McCabe gives us minimum Reflux.
4 - Question
Gilliland Correlation is arranged to estimate the
a) Numbers of Stages
b) Numbers of Reboiler
c) Numbers of Feed
d) Numbers of Column
View Answer
Answer: a
Explanation: Gilliland Correlation is arranged to estimate the Numbers of Stages at finite reflux ratio, while reboiler is only a unit piece of set.
5 - Question
Gilliland’s y intercept is given as
a) Nmin/N+1
b) N-Nmin/N+1
c) N+Nmin/N+1
d) N/N+1
View Answer
Answer: b
Explanation: Gilliland represented correlation graphically as, N-Nmin/N+1 on y axis, where N is the number of stages.
6 - Question
Gilliland’s x intercept is given as
a) Rmin/R+1
b) R/R+1
c) Nmin/R+1
d) R-Rmin/R+1
View Answer
Answer: d
Explanation: Gilliland represented correlation graphically as R-Rmin/R+1 on x axis, where R is the reflux ratio of the system.
7 - Question
Optimum feed-stage location, can be obtained by using
a) Gilliland correlation
b) Kirk bride correlation
c) Fenske’s correlation
d) Sorel’s correlation
View Answer
Answer: b
Explanation: An approximate optimum feed-stage location, can be obtained by Equation of Kirk bride correlation while Gilliland correlation is used to plot intercepts.
8 - Question
For Multicomponent Mixtures Equilibria depend on ?
a) Pressure
b) Temperature
c) Humidity
d) Enthalpy
View Answer
Answer: b
Explanation: It depends on T, which changes from stage to stage, Pressure is not the deciding criteria as it can vary from Colum to column.
9 - Question
In multicomponent distillation, the separation of components is calculated using
a) Assumed flows of species
b) Assumed flows of reflux
c) Assumed flows of Vapor
d) Assumed flows of liquid
View Answer
Answer: c
Explanation: The number of plates above and below the feed is assumed, and the separation is calculated using assumed reflux.
10 - Question
Once the components are identified, in a multicomponent distillation they are called
a) Key Components
b) Mixed Components
c) Flow Components
d) Gain Components
View Answer
Answer: a
Explanation: Once the components are identified, they are called Key Components, the components which are hence mixed in a single stage rate called mixed components.